vallmo
Forum Junior
Topics: 25
Posts: 37
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The following questions have I found on a page from a British university:
True or false:
1. In the control of blood pressure by the kidney
a. Renin is secreted at a constant rate [F] Its secretion is influenced by blood pressure, Na+ load
b. Renin acts directly on the adrenal glands to cause aldosterone secretion [F] It converts angiotensinogen to angiotensin 1
c. Renin is synthesised by the Macula Densa cells [F] By the granular cells
d. The rate of filtration influences the secretion of renin [T] Because it will affect Na+ delivery to distal tubule
e. The rate of filtration is controlled by tubulo-glomerular feedback [T] Na+ load is sensed by the macula densa cells and they signal to the glomerulus to alter filtration rate
2. In the nephron
a. The proximal tubule is impermeable to water [F] 60-70% of filtered water is reabsorbed here
b. The proximal tubule can secrete water [F] Water moves passively down concentration gradients
c. Water movements follow osmotic gradients [T] See above
d. Water movement can flow against NaCl gradients [F] Osmotic gradients are set up by first pumping Na+, Cl- follows and this establishes the osmotic gradient for water movement
e. Water entering the collecting duct causes the release of ADH [F] ADH released in response to increasing osmolarity (fall in water)
3. In the process of reabsorption by the proximal tubule in the kidney
a. Primary active transport is energy dependent [T] Na+/K+-ATPases hydrolyse ATP
b. Secondary active transport uses energy [F] They rely on Na+ gradient
c. Sodium-potassium ATPase pumps K+ into the interstitium[F] They pump it into the cell
d. Na+/H+ exchange occurs across the basolateral membrane [F] It occurs across the luminal (apical) membrane
e. H+/HCO3- exchange occurs at the luminal membrane [F] It occurs across the basolateral membrane to move HCO3- into interstitium
4. The kidney
a. Contains 1 million nephrons [T] Range 1-1.5M per kidney
b. Is not lobular in the human foetus [F] It is lobular in the foetus and fused in the adult
c. Has a higher NaCl concentration in the cortex than the medulla [F] The medulla has a high osmolarity (1200-1400mOsmol/L)
d. Is able to produce hypertonic urine in humans [T] Theoretically, up to 1200mOsmol/L with maximum ADH (antidiuretic hormone)
e. Is a major site of vitD storage in the body [T] VitD made in liver stored in kidneys
5. In the process of capillary exchange
a. The hydrostatic pressure in the capillaries is always greater than that in the interstitium [T] Pcap varies from 25mmHg to 12mmHg, whereas Pinterstitium, while difficult to measure, ranges between 4 to -8mmHg and is therefore ignored in fluid exchange calculations
b. The capillary hydrostatic pressure is always greater than the oncotic pressure [F] Pcap falls to 12mmHg at venular end while oncotic pressure is 25mmHg
c. The oncotic pressure in the interstitium is effectively zero [T] Because the protein concentration is negligible
d. Plasma oncotic pressure decreases from the arteriolar to the venular end of the capillary [F] Plasma proteins, which give rise to oncotic pressure, do no change in concentration
e. Capillary uptake occurs along the whole length of a capillary bed [F] Only where Pcap falls below the plasma oncotic pressure (venular end of capillary bed)
6. In the control of body fluid and electrolytes
a. Atrial natriuretic peptide (ANP) causes diuresis [F] No, natriuretic means "salt losing" . It causes Na+ (and Cl-) excretion
b. ANP causes salt retention [F] It causes salt excretion
c. ANP inhibits aldosterone secretion [T] ANP and aldosterone have opposite effects and are mutually inhibitory
d. Aldosterone causes Na+ reabsorption [T] By increasing Na+ permeability of the luminal membrane in the distal tubuleand the activity of Na-pumps
e. Aldosterone reduces plasma osmolarity [F] It causes Na+ reabsorption and therefore increases osmolarity
7. In the regulation of body fluid pH
a. The rate of H+ ion secretion is inversely proportional to pH [T] High pH - low H+ secretion
b. pH can be influenced by ammonia secretion [T] Yes, by the loss of ammonium (NH3 + H+ = NH4+)
c. Urea is a blood buffer [F] bicarbonate, haemaglobin, plasma proteins, phosphate
d. The renal response to acidosis is to decrease H+ secretion [F]To increase H+ secretion, thereby making plasma less acidic
e. 90% of filtered HCO3- is reabsorbed [T] Yes, it is an esential blood buffer
8. In the kidney
a. The vasa recta supply blood to the Loops of Henle [T] As well as removing some solute and water from the medullary region
b. Juxtamedullary nephrons have short Loops of Henle [F] Cortical nephrons (85%) have short loops - juxtamedullary (15%) have long loops
c. The thick ascending limb of the Loop of Henle is impermeable to water [T] It pumps Na+ into the interstitium, chloride follows but NOT water. It is referred to as the "diluting" segment
d. The blood leaving the glomerulus is carried by an efferent arteriole [T] This is unusual, but the function of the glomerular capillary bed is filtration rather than O2 delivery
e. The glomerular capillaries are less permeable than normal capillaries [F] No. they are MORE permeable
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| mjl1717
Forum Hero
Topics: 958
Posts: 5,463
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Even if you dont get any responses think of these 2 days as kidney warm ups. Im a little tied up right now but in the next 24 hrs Ill be in the foxhole with you! {For those who dont know a foxhole is a strategic alcove when engaged in a battle ](*,) [-o<
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Smell the coffee! "Is That an Osler move??"
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